A recurring theme might be the struggle for acceptance. People might have certain expectations of her because she's related to Harry. Some might expect her to be just as brave or talented as him, while others might be jealous or suspicious. So, the fanfiction could focus on how Lucy deals with these different attitudes and tries to be accepted for who she really is in the wizarding community.
The theme of identity is very prevalent. As Draco's sister, she has to figure out who she is apart from her family name. There's also the theme of secrecy. She may have to keep certain things about herself or her actions from her family. And love, not just romantic love but also platonic love for her new friends, is a common theme as it often drives her actions and decisions in the fanfictions.
The exploration of family legacies is also a common theme. Harry's family has a reputation for being against the Dark Arts, while Draco's family has a more complicated history. Fanfictions might show how Harry Potter's sister and Draco Malfoy deal with the expectations and shadows of their respective family legacies. It could be that they both try to break free from the constraints of their family's pasts and create their own identities together.
One interesting fanfiction could be where Lucy discovers she has a unique magical ability that even Harry doesn't have. Maybe she can communicate with magical creatures on a deeper level. In this story, she uses her ability to solve a mystery in Hogwarts that has been baffling everyone. It could show her growing up in the shadow of her famous brother but still making her own mark in the wizarding world.
One common theme is family. Since it's about Harry having a little sister, it often explores the family dynamic. How they support each other, protect one another, and sometimes even have sibling rivalries. Another theme is identity. The little sister has to figure out who she is in the shadow of her famous brother.
A lot of these fanfictions explore the concept of family. How does her being in Slytherin affect her relationship with Harry and other family members? Also, the theme of acceptance. The sister has to deal with the fact that Slytherin has a bad reputation in the wizarding world, and she has to find acceptance within that house and from others. For example, in some fanfics, she has to prove that she's not like the 'evil' Slytherins people expect.
Love and relationships are also a big theme. She could fall in love with someone from a different background, like a half - blood or a Muggle - born. This would cause a lot of drama, especially considering her family's views. It would be a story of defying the odds and following her heart.
A third common theme is the exploration of new magical adventures. Writers of fanfiction love to send Harry and Lucy on quests that neither of them could have had in their original stories. These adventures might involve exploring new magical lands that are a blend of Narnia and Hogwarts - like settings, or encountering strange and powerful magical creatures that are a combination of the ones from both series. This theme adds an element of excitement and novelty to the fanfictions.
One common theme is family loyalty. Since they are siblings, the stories often focus on how they support and protect each other. Another theme is the discovery of self. The sister, who may have been hidden or in the background, often has to figure out who she is in relation to Harry and the wizarding world. Also, the theme of facing challenges together is prevalent. They join forces to take on the threats in the wizarding world, just like Harry did with his friends in the original series.
The theme of family also plays a big role. James's sister is part of the Potter family, and Sirius's own family situation was quite complex. Fanfictions might explore how their different family backgrounds interact and influence their relationship. For instance, Sirius might find the warmth and normalcy of the Potter family appealing, especially when compared to his own dark family history.
Another theme could be growth. The experience of pregnancy often forces a character to grow and change. So, in these fanfictions, we might see Lucy becoming more responsible, more empathetic, and stronger as she faces the challenges of pregnancy.